A lot of people have said that they see repetition of words and phrases in the output they get from ChatGPT. Here's a really simple script to avoid it and to show you what it has repeated at the end of the output.
Replace NNN with the rough number of words you want in the essay
Replace [SUBJECT] with what you want the essay on
Replace [XXX] with how much of a gap you want before repetition is allowed
PROMPT:
Write me an NNN word essay on [SUBJECT]. You must only use specific verbs, nouns, adjectives, and pronouns once in every XXX words of the output and then use alternative synonyms. This does not apply to prepositions, conjunctions, and indefinite articles. When complete read the output fully and list any words that are repeated. Give an accurate count for each repeated word. Double check to make sure the repetition count is accurate. Ignore prepositions, conjunctions, and indefinite articles in the repetition count.